#include <iostream>
using namespace std;

class Func {
public:
	double operator() (double d) const {
		return d*d;
	}
	double operator() (int a, int b) const {
		return a+b;
	}
};

int main (void)
{
	Func func;
	//func.operator()(3.14)
	cout << func(3.14) << endl;
	cout << func (100, 200) << endl;
	return 0;
}
